939010271 - 5040DD Check operation of pollution sensor (AQS) (Automatic Air Conditioning)
With the Examiner in voltmeter mode, select 20 Volts full scale deflection and 200 milliseconds base timeConnect the black probe of an Examiner to the vehicle earth and the red probe to pin 3 of the air quality sensor output signal See K064 EXHAUST GAS PRESENCE SENSORTurn the key to the ON position.Wait about 36 secs for the sensor to warm up.Spray the gas in the canister (part no. 71715571) in less than 60 seconds.Press the START button.The signal shown should be a set of PWM impulses with a frequency of 100 Hz and a Duty Cycle that varies between 15 and 70% as indicated in the table below.
PWM% Duty Cycle = T1 / T2 where:
T1= duration of impulse
T2 = 1/f = 1/100 Hz = Duratation of transmission
Pin out:
1. +CH/15
2. earth
3. output signal
PWM signal meaning5% short circuit to earth of signal line15% non polluted air circulation30% level 1 pollution50% level 2 pollution70% level 3 pollution>90% short circuit +12 signal line
